Steroidal glycosides from Allium cyrillii bulbs

Abstract

Two spirostanol saponins, one of which was a new compound, were isolated among the steroidal glycosides of Allium cyrillii Ten. Bulbs. The structures of these glycosides were established using chemical and spectral analytical methods as E-D-glycopyranosyl-(Steroidal glycosides represent a broad class of natural saponins, which are interesting to researchers because of their broad spectrum of biological activity and ecological safety [1].Plants of the genus Allium, which are indigenous to Crimea, are promising in the search for saponin-bearing species. Moreover, data on the steroidal glycosides of the majority of Crimean species have not been reported. Hence the study of the chemical structure of steroidal glycosides from representatives of the Alliaceae family is timely.Bulbs of A. cyrillii yielded chromatographically pure glycosides 1 (0.085 g) and 2 (0.154 g). The aglycon of both compounds was identified after acid hydrolysis as gitogenin [2]. TLC and comparison with authentic sugar samples detected glucose, xylose, and galactose in a 2:1:1 ratio. Alkaline hydrolysis of 1 and TLC using an authentic standard detected 3-hydroxy-3-methylglutaric acid (3, HMG) as a substituent. The empirical formulas of 1 and 2 were determined as C 56 H 90 O 27 and C 50 H 82 O 23 . These were confirmed as peaks of negative ions [M -H] -in mass spectra with m/z 1193.5602 and 1049.5149 that correlated to molecular weights (MWs) 1194.5680 and 1050.5228 Da (calculated MWs 1194.5670 and 1050.5247 Da, respectively). The 13 C NMR spectrum of 1 ( Table 1) showed resonances of the carbohydrate part and the HMG residue as 27 C atom resonances including 4 methyl (G 13.3, 15.0, 16.6, 17.3), 10 methylene, 10 methine, and 3 quaternary (G 36.8, 40.8, 109.4) atoms. The spectrum of 2 also contained 27 resonances for C atoms of the aglycon. The PMR and 13 C NMR spectra indicated that 1 and 2 were spirostane derivatives. Thus, the 13 C chemical shift (CS) of C-22 in both compounds was 109.4 ppm.

Spirostanol Saponins from Flowers of Allium Porrum and Related Compounds Indicating Cytotoxic Activity and Affecting Nitric Oxide Production Inhibitory Effect in Peritoneal Macrophages

“…In addition, a 2-dehydro derivative was isolated from a mutant of Allium ampeloprasum, reported as yayoisaponin B [16]. Two other related saponins, structurally identified as 6-deoxy-aginoside (formerly known also as F-gitonin) and 6-epi-aginoside, were isolated from Allium cyrillii [25] and from Allium jesdianum [26]. Aginoside and its 25S epimer, were identified in Allium schubertii bulbs [27].…”